Global Patent Index - EP 0833148 B1

EP 0833148 B1 20041103 - A method and a device for controlling an air /fuel ratio sensor

Title (en)

A method and a device for controlling an air /fuel ratio sensor

Title (de)

Verfahren und Vorrichtung zur Kontrolle eines Luft-Kraftstoff Verhältnissensors

Title (fr)

Méthode et dispositif de contrôle pour un capteur de rapport air-carburant

Publication

EP 0833148 B1 20041103 (EN)

Application

EP 97116325 A 19970919

Priority

JP 28033196 A 19960930

Abstract (en)

[origin: EP0833148A2] An air/fuel ratio sensor is controlled such that the oxygen concentration of the measurement gas can be detected from a pump current substantially instantaneously after a heater turns on. In the air/fuel ratio sensor an oxygen pumping cell and an oxygen concentration measuring cell are each formed of a solid electrolytic layer interposed between a pair of porous electrodes. One of the electrodes of each cell defines a measurement gas chamber in which the diffusion of the measurement gas is controlled. After a micro current is supplied to the other electrode of the oxygen concentration measuring cell for a predetermined period of time, thereby forming an internal reference oxygen source, the supply of the micro current is stopped and at the same time a pump current in the oxygen pumping cell starts to be controlled until the interelectrode voltage of the oxygen concentration measuring cell reaches a target voltage. After the air/fuel ratio sensor is activated, the supply of the micro current is restarted. <IMAGE>

IPC 1-7

G01N 27/419; G01N 27/407; G01N 27/406; F02D 41/14

IPC 8 full level

G01N 27/41 (2006.01); G01N 27/406 (2006.01); G01N 27/419 (2006.01)

CPC (source: EP US)

G01N 27/4065 (2013.01 - EP US); G01N 27/419 (2013.01 - EP US)

Designated contracting state (EPC)

DE FR GB IT

DOCDB simple family (publication)

EP 0833148 A2 19980401; EP 0833148 A3 19981007; EP 0833148 B1 20041103; DE 69731445 D1 20041209; DE 69731445 T2 20051110; JP 3520163 B2 20040419; JP H10104195 A 19980424; US 5895564 A 19990420

DOCDB simple family (application)

EP 97116325 A 19970919; DE 69731445 T 19970919; JP 28033196 A 19960930; US 92752797 A 19970911